The chemical methods available for the degradation of proteins usually require the use of rather harsh conditions. The enzymatic methods suffer from high specificity for particular amino acids. There are a number of reports in the literature, starting with that of Collman and Buckingham in 1963, of Co(III) complexes that efficiently hydrolyze peptide and ester bonds. These complexes invariably contain a tetradentate ligand whose geometry is such that the cis positions in the octahedral complex are available and occupied by water molecules. The complexes act in a stoichiometric manner from the N terminal end. The rate of hydrolysis has only a small dependence on the nature of the amino acid residue at the peptide bond, making them potentially useful for direct sequence determination. The complexes bring about the total hydrolysis of large proteins, at pH 8-10 and at moderate temperatures. We will further develop methods for the quantitative release and recovery of the amino acids from the cobalt complexes. Since the rate and pH profile of the reaction depends on the nature of the tetradentate ligand we will examine several additional complexes. The most attractive are those containing unsaturated ligands capable of d-pi back bonding with the cobalt. This is known to make other positions more exchange labile. The 2,2'-bipyridyl complex and the 1,6-bis(2-pyridyl)- 2,4-diazahexane complexes will be prepared. The rate, pH profile and selectivity of these complexes will be determined. If it appears desirable derivatives with the pyridine rings substituted with electron withdrawing groups will be prepared to move the pH maximum towards neutrality. The techniques of directly interfacing these methods with an amino acid analyzer will be explored.